The nervous system exerts a profound effect on the inflammatory response. Antidromic stimulation of sensory nerves results in localized vasodilation and increased vascular permeability (Janecso et al. Br. J. Pharmacol. 1967, 31, 138-151) and a similar response is observed following injection of peptides known to be present in sensory nerves. From this and other data it is postulated that peptides released from sensory nerve endings mediate many inflammatory responses in tissues like skin, joint, urinary tract, eye, meninges, gastro-intestinal and respiratory tracts. Hence inhibition of sensory nerve peptide release and/or activity, may be useful in treatment of, for example arthritis, dermatitis, rhinitis, asthma, cystitis, gingivitis, thrombophielites, glaucoma, gastro-intestinal diseases or migraine. In U.S. Pat. Nos. 4,383,999 and 4,514,414 and in EP 236342 as well as in EP 231996 some derivatives of N-(4,4-disubstituted-3-butenyl)azaheterocyclic carboxylic acids are claimed as inhibitors of GABA uptake. In EP 342635 and EP 374801, N-substituted azaheterocyclic carboxylic acids in which an oxime ether group and vinyl ether group forms part of the N-substituent respectively are claimed as inhibitors of GABA uptake. Further, in WO 9107389 and WO 9220658, N-substituted azacyclic carboxylic acids are claimed as GABA uptake inhibitors. EP 221572 claims that 1-aryloxyalkylpyridine-3-carboxylic acids are inhibitors of GABA uptake.
In addition to the above cited references, U.S. Pat. No. 3,074,953 discloses 1-(3-(10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-prop yl)-4-phenyl-4-piperidinecarboxylic acid ethyl ester as a psychotropic drug. Analogous 1-substituted 4-phenyl-4-piperidinecarboxylic acid ester derivatives to the above cited compound are described (J. Med. Chem. 1967, 10, 627-635 and J. Org. Chem. 1962, 27, 230-240) as analgesics, antispasmodics and psychotropics. In JP 49032544, JP 48040357, FR 2121423, GB 1294550 and DE 21 01066, 1-substituted 4-dialkylamino-4-piperidinecarboxamides are disclosed as psychotropic agents, for the treatment of schizophrenia and as inhibitors of inflammation.